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Showa SFF negative prssure when bleeding

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I have a 47mm showa sff Fork I am rebuilding. I have rebuilt plenty of forks but I am having trouble bleeding this one. I am following the manual and for what ever reason when bleeding the damper rod, Instead of the rod extending when pushed in, the inner rod gets sucked inward instead of pushing outward. I believe I read about this in a post before but can't find it.

 

The steps I am following to bleed are as follows.

 

pour 9.3 oz in inner cartridge

move inner rod up and down - manual says a couple of times I move the rod up and down 10+ strokes going all the way in and all the way out slowly.  

Then I measure the fluid height and install the mid-valve assembly.

After installing the assembly I move the rod up and down again.

 

Once I have done about 6 strokes up and down the inner rod gets its negative pressure and sucks the inner rod inward instead of pushing it outward.

 

The other weird thing is when I took the forks apart the inner cartridge had the same negative pressure. I had a local well known suspension guy valve the suspension last season. Could this be a valving set up issue? I usually have my suspension valved and then handle he fluid changes afterwards.

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i also ride sff 47 on crf , i use high pressure seal on floating piston. your cartrige have negative pressure cause loose oil. you must check if loose from bottom seal . floating piston seal or floating piston o ring if u need a stack i can pm u

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i also ride sff 47 on crf , i use high pressure seal on floating piston. your cartrige have negative pressure cause loose oil. you must check if loose from bottom seal . floating piston seal or floating piston o ring if u need a stack i can pm u

 

I tried to bleed the inner damper again with no luck, I'm beginning to think that the seal on the midvalve assembly might be bad.

 

I plugged the holes up top and filled chamber

Then pulled inner rod down and toped chamber off

I then pushed the inner rod up and down 5-7 times and seen that there were no more bubbles

I pushed the inner rod up and pushed the mid valve assembly down into the inner cartridge while pulling the inner rod down and sucking the Midvale assembly down into cartridge and screwing it.  

Then I pushed the inner rod up into the cartridge and the excess oil comes out the two holes up top.

Then when I let go of the inner rod it does not even move under its own will .

I even try to pump the inner rod a couple of times and nothing.

 

I tried this procedure twice , with no luck, However it no longer gets negative pressure now and doesn't suck in on its own. It just doesn't extend on its own.

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I normally replace base valve seals and cartridge seals if the rod is not extending.

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... I'm beginning to think that the seal on the midvalve assembly might be bad.

 

...

I pushed the inner rod up and pushed the mid valve assembly down into the inner cartridge while pulling the inner rod down and sucking the Midvale assembly down into cartridge and screwing it.  

...

I guess you mean the right part - but named it false.

its the base valve assembly, or more detailed, the free piston or floating piston.

so probably - like cardinale 199 mentioned -  the floating piston seal or floating piston o ring is damaged

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I cant seem to find a part number on the floating piston seal or inner rod seal whats the best way to source one of these the oem parts diagram shows nothing.

1399930051637.jpg

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IwBIF7W.jpg

this is the seal of the piston, that you have to replace.

Edited by osiarg

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Race tech, do a product search on your bike... Or any dirt bike suspension specialist should be able to hook u up with those seals

Sent from my iPhone using Thumper Talk

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